Abstract
Here, we compare the efficiency and accuracy of remote sensing and plot-based methods for measuring vegetation cover for the understory and canopy of banksia woodland in an urban area of Western Australia. Methods compared were visual estimation, foliage cover computation from photographs, satellite imagery and aerial photographs. Observations and images from 1 m 2 , 100 m 2 and 625 m 2 quadrats measured cover of small plants, understory plants and trees respectively. Aerial photography and satellite imagery allowed the number, height and cover of trees to be estimated in 625 m 2 and 1 ha plots. The accuracy of methods was compared using a 28 month time series commencing before and after an intense bushfire that removed all foliage cover. Directly comparable methods were in close agreement and in combination allowed plant recovery to be quantified in great detail. Visual estimation of cover in the field was time-consuming but necessary to measure the contribution of individual species. Visual estimates from 1 m 2 downward photos allowed functional groups of plants to be measured. The number of green pixels selected manually in photographs confirmed that cover calculated from ground-based photographs using algorithms was accurate, except when cover was very low. We developed a new algorithm for computing cover from photographs that was accurate at low cover (Gperc). Canopy cover estimation by algorithm from upward photographs was subject to more errors, requiring exclusion of some images. Landsat satellite images allowed the impacts of severe drought and previous fires to be identified against a background of relatively consistent seasonal variations since 1988. Aerial photographs from 1953 onwards showed gradual recolonisation by banksia woodland trees over 60 years following tree felling. These methods provide a toolkit for monitoring vegetation recovery after disturbance and baseline data for monitoring banksia woodland. This toolkit should also be suitable for most other plant communities.
| Original language | English |
|---|---|
| Pages (from-to) | 33-54 |
| Number of pages | 22 |
| Journal | Remote Sensing in Ecology and Conservation |
| Volume | 5 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 1 Mar 2019 |
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A monitoring toolkit for banksia woodlands : comparison of different scale methods to measure recovery of vegetation after fire. / Brundrett, Mark; van Dongen, Ricky; Huntley, Bart; Tay, Natasha; Longman, Vanda.
In: Remote Sensing in Ecology and Conservation, Vol. 5, No. 1, 01.03.2019, p. 33-54.Research output: Contribution to journal › Article
TY - JOUR
T1 - A monitoring toolkit for banksia woodlands
T2 - comparison of different scale methods to measure recovery of vegetation after fire
AU - Brundrett, Mark
AU - van Dongen, Ricky
AU - Huntley, Bart
AU - Tay, Natasha
AU - Longman, Vanda
PY - 2019/3/1
Y1 - 2019/3/1
N2 - Here, we compare the efficiency and accuracy of remote sensing and plot-based methods for measuring vegetation cover for the understory and canopy of banksia woodland in an urban area of Western Australia. Methods compared were visual estimation, foliage cover computation from photographs, satellite imagery and aerial photographs. Observations and images from 1 m 2 , 100 m 2 and 625 m 2 quadrats measured cover of small plants, understory plants and trees respectively. Aerial photography and satellite imagery allowed the number, height and cover of trees to be estimated in 625 m 2 and 1 ha plots. The accuracy of methods was compared using a 28 month time series commencing before and after an intense bushfire that removed all foliage cover. Directly comparable methods were in close agreement and in combination allowed plant recovery to be quantified in great detail. Visual estimation of cover in the field was time-consuming but necessary to measure the contribution of individual species. Visual estimates from 1 m 2 downward photos allowed functional groups of plants to be measured. The number of green pixels selected manually in photographs confirmed that cover calculated from ground-based photographs using algorithms was accurate, except when cover was very low. We developed a new algorithm for computing cover from photographs that was accurate at low cover (Gperc). Canopy cover estimation by algorithm from upward photographs was subject to more errors, requiring exclusion of some images. Landsat satellite images allowed the impacts of severe drought and previous fires to be identified against a background of relatively consistent seasonal variations since 1988. Aerial photographs from 1953 onwards showed gradual recolonisation by banksia woodland trees over 60 years following tree felling. These methods provide a toolkit for monitoring vegetation recovery after disturbance and baseline data for monitoring banksia woodland. This toolkit should also be suitable for most other plant communities.
AB - Here, we compare the efficiency and accuracy of remote sensing and plot-based methods for measuring vegetation cover for the understory and canopy of banksia woodland in an urban area of Western Australia. Methods compared were visual estimation, foliage cover computation from photographs, satellite imagery and aerial photographs. Observations and images from 1 m 2 , 100 m 2 and 625 m 2 quadrats measured cover of small plants, understory plants and trees respectively. Aerial photography and satellite imagery allowed the number, height and cover of trees to be estimated in 625 m 2 and 1 ha plots. The accuracy of methods was compared using a 28 month time series commencing before and after an intense bushfire that removed all foliage cover. Directly comparable methods were in close agreement and in combination allowed plant recovery to be quantified in great detail. Visual estimation of cover in the field was time-consuming but necessary to measure the contribution of individual species. Visual estimates from 1 m 2 downward photos allowed functional groups of plants to be measured. The number of green pixels selected manually in photographs confirmed that cover calculated from ground-based photographs using algorithms was accurate, except when cover was very low. We developed a new algorithm for computing cover from photographs that was accurate at low cover (Gperc). Canopy cover estimation by algorithm from upward photographs was subject to more errors, requiring exclusion of some images. Landsat satellite images allowed the impacts of severe drought and previous fires to be identified against a background of relatively consistent seasonal variations since 1988. Aerial photographs from 1953 onwards showed gradual recolonisation by banksia woodland trees over 60 years following tree felling. These methods provide a toolkit for monitoring vegetation recovery after disturbance and baseline data for monitoring banksia woodland. This toolkit should also be suitable for most other plant communities.
KW - Banksia woodland
KW - comparison of methods
KW - fire impacts and recovery
KW - photographic monitoring
KW - remote sensing
KW - vegetation cover estimation
UR - http://www.scopus.com/inward/record.url?scp=85050886733&partnerID=8YFLogxK
U2 - 10.1002/rse2.88
DO - 10.1002/rse2.88
M3 - Article
VL - 5
SP - 33
EP - 54
JO - Remote Sensing in Ecology and Conservation
JF - Remote Sensing in Ecology and Conservation
SN - 2056-3485
IS - 1
ER -